/*
 * Copyright 2002-2018 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.validation;

import org.springframework.context.support.DefaultMessageSourceResolvable;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;

/**
 * Encapsulates an object error, that is, a global reason for rejecting
 * an object.
 *
 * <p>See the {@link DefaultMessageCodesResolver} javadoc for details on
 * how a message code list is built for an {@code ObjectError}.
 *
 * @author Juergen Hoeller
 * @see FieldError
 * @see DefaultMessageCodesResolver
 * @since 10.03.2003
 */
@SuppressWarnings("serial")
public class ObjectError extends DefaultMessageSourceResolvable {

    private final String objectName;

    @Nullable
    private transient Object source;


    /**
     * Create a new instance of the ObjectError class.
     *
     * @param objectName the name of the affected object
     * @param defaultMessage the default message to be used to resolve this message
     */
    public ObjectError(String objectName, String defaultMessage) {
        this(objectName, null, null, defaultMessage);
    }

    /**
     * Create a new instance of the ObjectError class.
     *
     * @param objectName the name of the affected object
     * @param codes the codes to be used to resolve this message
     * @param arguments the array of arguments to be used to resolve this message
     * @param defaultMessage the default message to be used to resolve this message
     */
    public ObjectError(
            String objectName, @Nullable String[] codes, @Nullable Object[] arguments,
            @Nullable String defaultMessage) {

        super(codes, arguments, defaultMessage);
        Assert.notNull(objectName, "Object name must not be null");
        this.objectName = objectName;
    }


    /**
     * Return the name of the affected object.
     */
    public String getObjectName() {
        return this.objectName;
    }

    /**
     * Preserve the source behind this error: possibly an {@link Exception}
     * (typically {@link org.springframework.beans.PropertyAccessException})
     * or a Bean Validation {@link javax.validation.ConstraintViolation}.
     * <p>Note that any such source object is being stored as transient:
     * that is, it won't be part of a serialized error representation.
     *
     * @param source the source object
     * @since 5.0.4
     */
    public void wrap(Object source) {
        if (this.source != null) {
            throw new IllegalStateException("Already wrapping " + this.source);
        }
        this.source = source;
    }

    /**
     * Unwrap the source behind this error: possibly an {@link Exception}
     * (typically {@link org.springframework.beans.PropertyAccessException})
     * or a Bean Validation {@link javax.validation.ConstraintViolation}.
     * <p>The cause of the outermost exception will be introspected as well,
     * e.g. the underlying conversion exception or exception thrown from a setter
     * (instead of having to unwrap the {@code PropertyAccessException} in turn).
     *
     * @return the source object of the given type
     * @throws IllegalArgumentException if no such source object is available
     * (i.e. none specified or not available anymore after deserialization)
     * @since 5.0.4
     */
    public <T> T unwrap(Class<T> sourceType) {
        if (sourceType.isInstance(this.source)) {
            return sourceType.cast(this.source);
        } else if (this.source instanceof Throwable) {
            Throwable cause = ((Throwable) this.source).getCause();
            if (sourceType.isInstance(cause)) {
                return sourceType.cast(cause);
            }
        }
        throw new IllegalArgumentException("No source object of the given type available: " + sourceType);
    }

    /**
     * Check the source behind this error: possibly an {@link Exception}
     * (typically {@link org.springframework.beans.PropertyAccessException})
     * or a Bean Validation {@link javax.validation.ConstraintViolation}.
     * <p>The cause of the outermost exception will be introspected as well,
     * e.g. the underlying conversion exception or exception thrown from a setter
     * (instead of having to unwrap the {@code PropertyAccessException} in turn).
     *
     * @return whether this error has been caused by a source object of the given type
     * @since 5.0.4
     */
    public boolean contains(Class<?> sourceType) {
        return (sourceType.isInstance(this.source) ||
                (this.source instanceof Throwable && sourceType.isInstance(((Throwable) this.source).getCause())));
    }


    @Override
    public boolean equals(@Nullable Object other) {
        if (this == other) {
            return true;
        }
        if (other == null || other.getClass() != getClass() || !super.equals(other)) {
            return false;
        }
        ObjectError otherError = (ObjectError) other;
        return getObjectName().equals(otherError.getObjectName());
    }

    @Override
    public int hashCode() {
        return super.hashCode() * 29 + getObjectName().hashCode();
    }

    @Override
    public String toString() {
        return "Error in object '" + this.objectName + "': " + resolvableToString();
    }

}
